LOS ANGELES – The U.S. Coast Guard and Navy were searching early Friday for as many as nine people off the Southern California coast following a collision between a Coast Guard plane and a Marine Corps helicopter, officials said.

The crash was reported at 7:10 p.m. Thursday, about 50 miles off the San Diego County coast and 15 miles east of San Clemente Island, Coast Guard spokeswoman Petty Officer Allyson Conroy said.

A pilot reported seeing a fireball near where the aircraft collided, Federal Aviation Administration spokesman Ian Gregor said, and the Coast Guard informed the FAA that debris from a C-130 had been spotted. Seven people were on board the plane, a C-130, and two people were aboard the helicopter, he said.

Cpl Michael Stevens, a spokesman for the Miramar Marine Corps Air Station, said the AH-1W Super Cobra helicopter was on a training mission when it went down. The Cobra and its crew are part of Marine Aircraft Group 39, based at Camp Pendleton, and the 3rd Marine Aircraft Wing, which is headquartered at Miramar, Stevens said.

The missing Coast Guard plane and its crew are from Coast Guard Air Station Sacramento, said Coast Guard Petty Officer 2nd Class Jetta Disco. Crews from the Sacramento Coast Guard station fly search-and-rescue, law enforcement and logistics missions, Disco said.

The Coast Guard planned to search through the night, having sent three cutters and diverting an MH-60 Jayhawk helicopter to the area to search for survivors. The Navy, meanwhile, sent four vessels and multiple helicopters.

"The search condition are ideal for tonight," Lt. Josh Nelson of the Coast Guard told XETV in San Diego. "We've got a clear sky, the winds are calm, the seas are calm, and we have a lot of assets out there."

San Clemente Island is the southernmost of the eight Channel Islands located 68 nautical miles west of San Diego. The Navy has owned and trained at San Clemente Island since 1934, according to the island's Web site. Naval Air Station, North Island is responsible for the island's administration.

Earlier this week, it was an AH-1 Cobra attack helicopter that collided with a UH-1 helicopter over southern Afghanistan, killing four American troops and wounding two more, a Marine spokesman said.

Heard about this at my job not long ago and was told that one of the crew members aboard the 130 is the son of one of our day shift co-workers (not sure if true yet). In any case, I hope someone is found...